CVE-2020-28026
CVE-2020-28026 is a critical-severity vulnerability in Exim with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.
Key facts
- Severity: Critical (CVSS 3.x base score 9.8)
- CVSS v2: 9.3
- EPSS exploit prediction: 9% (95th percentile)
- Actively exploited: Not listed in CISA KEV
- Affected product: Exim
- Published:
- Last modified:
Description
Exim 4 before 4.94.2 has Improper Neutralization of Line Delimiters, relevant in non-default configurations that enable Delivery Status Notification (DSN). Certain uses of ORCPT= can place a newline into a spool header file, and indirectly allow unauthenticated remote attackers to execute arbitrary commands as root.
Frequently asked questions
- What is CVE-2020-28026?
- Exim 4 before 4.94.2 has Improper Neutralization of Line Delimiters, relevant in non-default configurations that enable Delivery Status Notification (DSN). Certain uses of ORCPT= can place a newline into a spool header file, and indirectly allow unauthenticated remote attackers to execute arbitrary commands as root.
- How severe is CVE-2020-28026?
- CVE-2020-28026 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2020-28026 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 9% (95th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2020-28026?
- CVE-2020-28026 affects Exim. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2020-28026?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- When was CVE-2020-28026 published?
- CVE-2020-28026 was published on 2021-05-06 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:a:exim:exim:*:*:*:*:*:*:*:*
More vulnerabilities in Exim
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- CVE-2023-42117 — Critical (CVSS 9.8): Exim Improper Neutralization of Special Elements Remote Code Execution Vulnerability. This vulnerability allows remote…
- CVE-2023-42116 — Critical (CVSS 9.8): Exim SMTP Challenge Stack-based Buffer Overflow Remote Code Execution Vulnerability. This vulnerability allows remote…
- CVE-2023-42115 — Critical (CVSS 9.8): Exim AUTH Out-Of-Bounds Write Remote Code Execution Vulnerability. This vulnerability allows remote attackers to…
- CVE-2022-37452 — Critical (CVSS 9.8): Exim before 4.95 has a heap-based buffer overflow for the alias list in host_name_lookup in host.c when…
- CVE-2020-28024 — Critical (CVSS 9.8): Exim 4 before 4.94.2 allows Buffer Underwrite that may result in unauthenticated remote attackers executing arbitrary…
Threat intelligence
Threat-intel indicators referencing this CVE:
- 76.12.128.249 (ipv4-addr)
- 50.116.72.139 (ipv4-addr)
- 166.62.41.190 (ipv4-addr)
- 132.148.155.138 (ipv4-addr)
- 50.62.22.47 (ipv4-addr)
- 31.131.22.122 (ipv4-addr)
- 193.68.57.43 (ipv4-addr)
- 192.169.201.223 (ipv4-addr)